Yamaha Srev1 Sampling Reverberator

Every couple of years a new technical paradigm is broached in the audio industry that results in a number of new products that become “must haves” for the studio. For example, in recent years we’ve had MIDI (which begot keyboards and sequencers) and then sampling technology (which ultimately begot DAWs) that suddenly caused not only the most commonly used studio gear to change, but the way we work as well. Now a technology called convolution looks to be the next wave, and the new Yamaha SREV1 sampling reverberator is one of the first products to utilize it.

Enter Convolution

But what exactly is convolution? Simply put, convolution is the process of taking an impulse response of either an environment (as in the case of the SREV1) or device and mapping the results for later use. An impulse response reveals everything about a room since an impulse carries equal energy at all frequencies. What we discover, in the form of reverberation, is the room’s response to that instantaneous, all-frequency burst. With some well-placed microphones to document the “fingerprint” (as Yamaha calls it) of the room, we can then add that response (in this case the exact room characteristic) to any digitized dry sound. The problem with convolution, until recentl, that is, was that a lot of computational horsepower was required in order to properly map all of the possible parameter permutations, then reproduce those parameters in an expedient manner later. But computer horsepower is now cheap enough that convolution is about to come to the masses, and the Yamaha SREV1 is one of the first examples of the technology. As a result, it’s now possible to have accurate, usable samples of a number of rather famous acoustic environments brought to your studio with utter precision.

The Details

Basically, the SREV1 is a 4-channel reverb that can be configured either as a 4-channel surround reverb or two fully independent stereo reverbs, each with its own inputs, outputs, and program settings. Thirty-two convolution chips provide the necessary horsepower for real-time convolution of up to 5.5 seconds per channel in stereo and 2.73 for 4-channel mode. An expansion module that doubles the available convolution time to almost 11 seconds for stereo and about 5 1/2 for 4-channel is also available.

The SREV1 comes with two AES inputs and outputs (four channels worth) and two YGDAI (Yamaha General Digital Audio Interface) slots for various analog and digital I/O options (such as ADAT or TASCAM TDIF). Inputs can be assigned to channels individually, allowing various input and output configurations. In stereo mode, a single input can be assigned to both channels for a mono in, stereo out operation or stereo in and stereo output. In surround mode, the unit can be configured for either mono or stereo in and 4-channel out. All inputs and outputs are 24-bit with 32-bit internal signal processing. The sample rates supported are 44.1 and 48 kHz, which can be sync’d via external word clock.

Up to four SREV1’s can be controlled using the optional remote, which features a large 320 x 240 graphical display complete with a fluorescent backlight, four motorized faders for parameter editing, and input and output clip indicators. Even though the remote is an option, you really need it since there’re no user controls (except for the on/off switch) on the SREV1 basic unit itself. That being said, the remote is simplicity itself, intuitive enough to enable just about any user to get going on the machine instantly.

There are four main pages on the remote, each accessed via a simple button on the top panel. The Program button selects reverb sample, library and project pages. There are two buttons dedicated to parameter adjustments; Parameter Main, which selects reverb decay and predelay, and Parameter Fine, which selects the pre-EQ and post-EQ pages. The final button is Utility, which selects the setup, digital I/O, metering, and MIDI pages.

The programs supplied with the unit are a nice cross-section of usable environments. A “Quick Memory” brings up Concertgebouw, Konzerthaus Mozart, Manhattan Center, Kings College Chapel, Nippon Budokan, Plate, Cello Studio 1, Avatar Studio A, Warm Wooden Church, and Act City Hamamatzu. Thirty-two additional programs are also available on the supplied CD-ROM, with additional libraries planned for the future.

Although it’s possible for users to sample their own rooms via Yamaha’s IRSampler and IREdit PC-based programs included on the CD-ROM, the necessary computer hardware for this operation was not included (serial cable and PCMCIA memory card).

The manual is excellent, being very complete and easy to use. One of the nice things is that there’s a short explanation as to what exactly is happening when editing parameters, which really does help you better tailor the sound for the application.

In Use

I used the SREV1 on surround mixes for English prog rockers Brand X, blues legend Joe Houston, and metal band Steamroller — all with impressive results. Unlike most other reverbs (which, as a category, seem more difficult to operate than they ought to be), this unit is very easy to use, so much so that I used it successfully for several weeks before I decided to crack open the manual. And the room samples are indeed impressive. It’s great to be able to add that great sounding Avatar room to a mix without having to make the cross-country trek to NYC. Just dial up the program, close your eyes, and you’re there.

While it’s a shame that the SREV1 can’t sample at 96k, I managed to use it on some DVD-A projects all the same. In these cases, I simply used the unit in its analog mode and printed the output of the ’verb back to four tracks on the DAW and proceeded as normal.

The Yamaha SREV1 takes reverb to another level. If only the real thing will do, then the SREV1 is the one to consider. It is unsurpassed in ease of use, and will add a level of realism to your mix seldom found in our current digital world.

Surround Professional Magazine